A galvanic cell is composed of two hydrogen electrodes, one of which is a standard one. In which of the following solutions should the other electrode be immersed to get maximum e.m.f.?
(a) 0.1 M HCl
(b) 0.1 M CH3COOH
(c) 0.1 M H3PO4
(d) 0.1 M H2SO4
(d) H2SO4 will furnish maximum H+.